Rollover grabs



Sept. 12, 1961 R. s. ELBERTY ROLLOVER GRABS 5 Sheets-Sheet 1 Filed Dec.21, 1956 INVENTOR ATTORNEY5 Sept. 12, 1961 R. s. ELBERTY 2,999,716

ROLLOVER GRABS Filed Dec. 21, 1956 3 Sheets-Sheet 2 mvsmpa ATTORNEY5ROLLOVER GRABS Filed Dec. 21, 1956 3 Sheets-Sheet 3 ATTORNEYS UnitedStates This invention relates to a grapple, and more particularly to agrapple adapted for lifting and manipulating metal coils, although itwill be understood that 1t can be employed in the lifting of otherobjects for transferring them. from one place to another.

In manipulating objects such as metal coils, for example, it isdesirable to have the grapple suspended either in a vertical or inclinedpostion when unloaded so that the object to be picked up, such as acoil, for example, may be readily grasped by the grapple. In the pastcounterweights have been employed in some instances to effect such aresult, but with such an arrangement the grapple may not be supportedeither in a horizontal or vertical position as desired but will besupported only in one of such positions.

Also it is desirable to provide for the coil to be suspended with itsaxis either in a vertical or horizontal position as some times oneposition is required and at other times another is desirable.

According to the present invention there is provided a grapple and abail for supporting the grapple from a crane hook or the like, thegrapple being movably mounted on the bail so that it may be moved tovarious positions so that regardless of the center of mass of thegrapple or of the grapple and weight thereon, the grapple or coilcarried by the grapple may be suspended either in a vertical orhorizontal position as desired. Another advantageous feature of thepresent invention is that of supporting the grapple upon the bail sothat it may be rotated to a given position with respect to the hail, therotation taking place about the approximate center of gravity of thecoil being lifted so that the load upon the rotating mechanism will begreatly reduced, it being obvious that much less effort is required torotate an object about its center of gravity than about a pointeccentric to the center of gravity.

One object of the present invention is to provide a grapple for liftingobjects such as metal coils, for example, which grapple may be rotatedwith respect to its supporting structure to occupy any desired positionwithin limits.

Still another object of the invention is to provide a grapple consistingof a supporting structure and a grapple structure, the latter beingcarried by a quadrant supported by the bail and movable with respect tothe bail so that the grapple may be supported in a desired angularposition with respect to the bail.

Still another object of the invention is to provide a grapple structurecomprising a bail and grapple mechanism movably carried by the bail andcooperating means on the bail and grapple structure by which the lattermay be rotated about a point without the bail, which point will beapproximately the center of gravity of the coil or other work carried bythe grapple.

To these and other ends the invention consists in the novel features andcombinations of parts to be hereinafter described and claimed;

In the accompanying drawings:

FIG. 1 is an end elevational view of a grapple embodying my invention;

FIG. 2 is a side elevational view thereof;

FIG. 3 is a partial sectional view on line 3-3 of FIG. 1;

FIG. 4 is a sectional view on line 4-4 of FIG. 2;

' atent O I 2,999,716 Patented Sept. 12, I961 ICE FIG. 5 is a sectionalview on line 5-5 of FIG. 3;

FIG. 6 is a sectional View on line 6-6 of FIG. 2;

FIG. 7 is a diagrammatic view showing a coil supported by the grapplewith its axis in a vertical position;

FIG. 8 is a similar view but showing the position of the part when theaxis of the coil is substantially horizontal;

FIG. 9 is a diagrammatic view showing automatic leveling switchesapplied to the grapple; and

FIG. 10 is a wiring diagram showing the operation of the levelingswitches.

To illustrate a preferred embodiment of the invention there is shown inthe drawings a bail structure A and a grapple mechanism B suspended fromthe bail structure as will be hereinafter explained.

As illustrated, the bail structure may comprise a pair of plates 10 and11 suitably secured together. A pin 12 is mounted at the upper ends ofthese plates which may be received in the hook 13 of a crane orappropriate lifting mechanism 14 so that the entire structure will bepivotally supported from this hook.

The plates 10 and 11 are relatively wide at their upper portions, asshown in FIG. 2, but also comprise narrower depending T-shaped arms 15,each having a laterally projecting extension 1 6 at its lower end andbetween these extensions 16 are mounted rollers 17, one of these rollersbeing at each end of the extensions;

Mounted on the plate 11 is an' electric motor 19 and a gear reductionunit 20, the latter having an output shaft 21 extending through theplates of the bail A and journaled therein. Secured to the shaft 21between the plates is a pinion 22 designed to be driven at a relativelyslow speed by the motor 19.

The grapple mechanism B includes a toothed quadrant 25 having teethv 2'6thereon and, as shown in FIGS. 2 and 6, this quadrant is movaby disposedbetween the arms 15 of the bail. The lower edge of the quadrant restsupon the rollers 17, and the teeth 26' mesh with those of the pinion 22so that upon energization of the motor 19 the quadrant will be movedwith respect to the bail. It will be noted that the radius of thequadrant is such that its center is a considerable distance below thebail and, as will be referred to hereinafter, the center lies atsubstantially the center of gravity of the average sized coil to behandled by the device so that the coils when rotated will be turnedsubstantially about the center of gravity thereof.

Secured to one end of the quadrant 25 is a substantially verticallydisposed frame member 27, and to this member is secured one end of asubstantially horizontal arm 28. The other end of this arm is secured tothe other end of the quadrant by the frame members 29 and 30 so that thearm 28, which carries the grapple jaws tobe hereinafter described, isrigidly connected to the quadrant 25.

As shown more especially in FIG. 4, the arm 28 comprises a pair ofspaced channel-shaped members 31 and 32, and it will be understood thatthe frame members 27 and 29 may also comprise spaced parallel elements,one secured to each of these channel-shaped members. Slidably mounted onthe arm 28 is a pair of cooperating jaw structures designated generallyby the numerals 33 and 34. The jaw member 33, as shown more particularlyin FIGS. 3 and 4, comprises ahollow rectangular upper portion 35slidably mounted on the arm 28 and embracing the channel members 31 and32. Secured to the element 35 are downwardly depending legs 36 and 37which are joined below the arm 28 by a transverse member 38.

Each of these arms is provided with a pair of elongated openings 39'and. 40; and slidably mounted in these openings are pins 41 and 42 whicharev secured to' rearwardly extending lugs 43 on a jaw member 44 whichmay,

as shown in FIG. 5, present a gripping surface 45 of armate form.Springs 46 connected at one end to the pin 42 and at their upper ends topins 47 secured in the arms 36 and 37 normally urge the jaws 44 upwardlyso that the pins 41 and 42 normally lie at the upper ends of the slots39 and 40. As shown in FIG. 3, the forward surface 48 of the member 38is inclined inwardly and downwardly, and the rear face 49 of the lug 43is complementally inclined so that when the jaw 44 moves downwardly oroutwardly along the member 38, it will be cammed toward the cooperatingjaw structure 34. Between the adjacent faces 48 and 49 may be mounted aseries of antifriction members such as rollers 50 to reduce the frictionbetween these parts.-

It will be understood that the jaw structure 34 is sub stantially likethe jaw structure 33 except that the depending legs, one of which isshown at 37 and the jaw member 44 are, for convenience, of shorterlength than the corresponding members of the jaw structure 33.

With this construction it will be apparent that when the jaws are causedto grab a coil or other piece of work, the weight of the coil as it islifted will cause the jaws to slide downwardly on the inclined members38 and 38 and, therefore, effect increased gripping pressure upon thecoil.

Nonrotatably mounted in the legs 36 and 37 of one of the jaw members 36and 37 of the other jaw member are nuts 51 (FIGS. 3 and 4) havingthreaded openings 52 therein in which are received the rightand lefthandthreaded portions 53 and 54 of a shaft 55 rotatably mounted between thelegs of the jaw members, as shown in FIG. 3. The outer end of this shafthas a bearing 56 in the outer end of the arm 28, and the inner end ofthe shaft is connected through a universal coupling 57 to the outputshaft 58 of a reduction gear unit 59 driven through a belt 60 from amotor 61 mounted upon the frame member 27.

With this construction it will be apparent that when the motor 61 isactuated, the shaft 55 will be rotated and the jaw members 44 and 44will be caused to approach each other or to separate depending upon thedirection of rotation of the shaft 55. The motor 61 will preferably be areversing motor so that the shaft can be rotated in either direction.

In FIG. 2 of the drawing the grapple mechanism B is shown in theposition it occupies when no load is supported thereon. It is noted thatthe quadrant 25 must be rotated in a counterclockwise direction to aslight extent so that the pinion 22 is at a short distance from theupper left-hand end of the quadrant, as shown in FIG. 2, in order thatthe arm 28 stand in a horizontal position and the jaws extend verticallyas would be desired if the grapple is to be used to lift a coil 63, theaxis of which is vertically disposed. When the parts are in the positionshown in FIG. 2, the center of gravity of the mechanism B falls directlybelow the pin 12.

It will be understood that when the coil is gripped by the grapple, thejaw 44 will lie within the coil and the jaw 44 will grip its exteriorsurface. When'the coil is lifted the center of gravity of the entireload including the grapple and coil will lie to the left of the centerof gravity of the grapple mechanism alone, and this would tend to tiltthe structure in a counterclockwise direction so that the center ofgravity would lie below the point of support at 12. In order to maintainthe axis of the coil vertical, the motor 19, which is a reversiblemotor, will be actuated in the proper direction to rotate the quadrantin a clockwise direction to the position, for example, shown in FIG. 7where the pinion 22 will be closer to the upper or lefthand end of thequadrant than before.

If it is desired to turn the coil to a horizontal position, the motor 19is energized in a direction to rotate the quadrant in a counterclockwisedirection and turn the quadrant and grapple mechanism B to the positionshown in FIG. 8 where again the center of gravity of the entire loadwill lie below the point of support 12. It will be apparent, therefore,that the load may be lifted in any desired position or lifted in oneposition and turned to another to be deposited, if that is desired.Moreover, the turning of the grapple mechanism takes place about an axislying within the coil and substantially at the center of the averagecoil to be handled so that the turning of the coil is effected with aminimum of elfort, thus reducing the load on the motor 19 and the teethof the pinion 22 and rack 26. a

So far as previously described, the motor 19 may be manually controlledin its operation. Under some circumstances it may be desirable toprovide for automatic control of the position of the grapple mechanismso that the arm 28 will be automatically maintained either in ahorizontal or a vertical position, thus maintaining the axis of the coileither vertical or horizontal. I have shown in FIGS. 9 and 10 of thedrawings a leveling switch mechanism by which this automatic control ofthe coil may be readily effected.

A switch mechanism 65 is mounted on the frame member 27 which isperpendicular to the arm 28, and a second switch member 66 is mounted onthe arm 28. The member 65 is provided with a pair of mercury switches 67and 68. [Wires 69 and 70 lead to the upper end of the switch 67, andlikewise wires 71 and 72 lead to the lower end of the switch 68. Asshown in FIG. 10 the wires 70 and 72 lead through a switch 73 to onepole 74 of a source of current, while the wire 69 leads to a pole of themotor which would actuate it in a reverse direction, while the wire 71leads to another pole of the motor to actuate it in a forward direction.A conductor 75 leads from the motor to the other pole 76 of the currentsource.

Similarly the switch member 66 comprises 'mercury switches 78 and 79under a similar arrangement to the switches 67 and 68 except that thesetwo switches are disposed in a substantially horizontal plane, while theswitches 67 and 68 are disposed in more nearly a vertical plane. It willbe seen, therefore, that when the arm '28 is horizontal, the mercurywill be at the lower ends of the members 78 and 79, and hence will notconnect the wires leading into the outer or upper ends of theseswitches. The switch 73 may, of course, be moved to connect the lead 74either with the switches 67 and 68 or with the switches 78 and 79depending upon whether it is desired to automatically maintain the coilwith its axis in a horizontal position or in a vertical position.

'If it is desired to maintain the load with its axis in a verticalposition (that is to maintain the arm 28 in a horizontal position), theswitch 73 is set, as shown in full lines in FIG. 10. In this case itwill be noted that both switches 78 and 79 are open, and the motor 19would remain at rest. However, if the arm 28 should tilt in a clockwisedirection from the horizontal, the mercury would flow to the other endof the tube of the switch 79, and thus close the circuit through thewires 80 and 81, the latter leading to the motor so as to actuate themotor in the proper direction to rotate the arm 28 in a clockwisedirection until it reached a level position.

If the arm 28 tipped in the other direction or counterclockwise, theswitch 78 would be closed across the wires 82 and 83 which would rotatethe motor in the opposite direction and turn the quadrant in a clockwisedirection.

During these movements the switch mechanism 65 would, of course, beinoperative due to the fact that it was out out of the circuit by theswitch 73.

However, if it is desired to maintain the axis of the coil in ahorizontal direction, as shown in FIG. 8, the switch 73 is thrown to itsdotted-line position, shown in FIG. 10, so that the switches 67 and 68become operative. If now the frame member 27 is in a vertical position,as shown in FIGS. 2 and 9, the wires 71 and 72 of the switch 68 will beconnected, thus driving the motor in a forward direction or in adirection to rotate the quadrant 25 counterclockwise so as to move thecoil to the position shown in FIG. 8.

If conditions are such that the center of gravity of the load supportedfrom the point of support 12 is such that the arm 28 is tilted in acounterclockwise direction from that shown in FIG. 8, then the switch 67would come into operation (provided the switch 73 is in its dotted-lineposition), and the motor 19 would be automatically set into operation torotate in the proper direction to move the quadrant in a clockwisedirection.

It will be noted that when a coil is grasped with its axis in a verticalposition, as shown in dotted lines in FIG. 2, there will be a tendency,due to the weight of the coil, for the coil to rotate in acounterclockwise direction, thus tending to urge the gripping jaw 44downwardly and the "ripping jaw 44 upwardly. On the other hand, when acoil is grasped with its axis in a horizontal position, there will be atendency, again due to the weight of the coil, for the coil to rotate ina clockwise direction, thus moving the gripping jaw 44 outwardly ortoward the remote end of the coil and the gripping jaw 44 inwardly. Itis desirably, therefore, in order to render the grapple of universalapplication for both jaw members to be movable and to be mounted on therollers 50 in order that they may move freely and grip the coil or otherwork tightly whether it is lifted when its axis is vertical orhorizontal.

While I have shown and described an embodiment of my invention, it willbe understood that it is not to be limited to all of the details shown,but is capable of modification and variation within the spirit of theinvention and within the scope of the claims.

What I claim is:

l. A grapple comprising an arm member, means for suspending said member,a pair of gripping jaws slidably mounted on said arm member for relativeapproaching and separating movements, means for actuating said jaws,each of said jaws comprising a leg member projecting from said arm insubstantial parallelism and a jaw member slidably mounted on each of theleg members, the contacting surfaces of each leg member and itsassociated jaw member being inclined toward the gripping surface of thecorresponding jaw member whereby relative movement between each jawmember and its associated leg member will efiect relative approaching orseparating movements of the jaw members and spring means urging each ofsaid jaw members in one direction along said inclined surface upon itsassociated leg member, said direction being that tending to separate thejaw members.

2. A grapple comprising a bail and grapple mechanism suspended by thebail, said bail comprising spaced members having rollers mountedtherebetween at their lower edges, said grapple mechanism comprising aquadrant member suspended from the bail with the lower edge of saidmember resting on said rollers, an arm mounted within the included angleof the quadrant and rigidly connected thereto to be supported thereby, apair of cooperating gripping jaws slidably mounted on said arm forrelative approaching and separating movements, motor means carried bythe quadrant, means connecting said motor means to the jaws to move thelatter to open and closed positions, a motor supported by the bail, apinion carried by the bail for rotation by said bail motor, and saidquadrant provided with teeth on its upper edge for engagement by saidpinion.

3. A grapple as in claim 2 wherein said arm comprises a pair of spacedmembers and including a threaded rod carried by said members, a pair ofnuts are threadably mounted on said rod between the spaced members, andeach of said nuts being connected to one of said jaws whereby rotationof the rod moves said jaws.

4. A grapple mechanism as in claim 2 wherein means are provided on thegrapple mechanism to automatically maintain said arm in a predeterminedposition with respect to the vertical, said means being responsive tothe deviation of the arm from such position and comprising agravity-actuated switch mounted on the grapple mechanism and connectedto the motor to control the same.

5. A grapple mechanism as in claim 2 wherein means are provided uponsaid grapple mechanism to maintain said arm in one of a plurality ofpredetermined positions, said means being responsive to deviation of thearm from such position and comprising a pair of gravity-actuatedswitches mounted on the grapple mechanism and means to connect either ofthese switches to the motor circuit to control energization of themotor.

6. A grapple, as in claim 2, wherein a pair of gripping jaws areslidably mounted on said arm for relative approaching and separatingmovements, means for actuating said jaws, each of said jaws comprising aleg member projecting from said arm in substantial parallelism and a jawmember slidably mounted on each of the leg members, the contractingsurfaces of each leg member and its associated jaw member being inclinedtoward the grip ping surface of the corresponding jaw member, wherebyrelative movement between each jaw member and its associated leg memberwill effect relative approaching or separating movements in the jawmembers and spring means urging each of said jaw members in onedirection along said inclined surface upon its associated leg member,said direction being that tending to separate the jaw members.

7. A grapple comprising a bail and grapple mechanism suspended by thebail, said bail comprising spaced members having rollers mountedtherebetween at their lower edges, said grapple mechanism comprising aquadrant member suspended from the bail with the lower edge of saidmember resting on said rollers, an arm mounted within the included angleof the quadrant and rigidly connected thereto to be supported thereby, apair of cooperating gripping jaws slidably mounted on said arm forrelative approaching and separating movements, motor means carried bythe quadrant, means connecting said motor means to the jaws to move thelatter to open and closed positions, a motor supported by the bail, andmeans connecting said bail motor to said quadrant member for rotatingsaid quadrant member when said bail motor is energized.

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